The bill is reportedly a long shot to pass in the Senate, which will debate it next week.

"After the fact, they're using the unelected Senate to kill something the elected House passed through. That's wrong," Cullen said, who wrote a letter to the Senate defending the way C-290 was handled.

Earlier this week, Justice Minister Rob Nicholson lobbied Tory senators on the merits of the bill.

Currently, Canadians can only bet on two or more games at a time. Four states in the U.S. allow bets on single games, including Nevada.

Major players from Las Vegas, like Caesars Entertainment and Las Vegas Sands, are all eyeing the market in Ontario as the province opens gambling to private interests.

Paul Burns, from the Canadian Gaming Association, said the whole North American industry has an interest in Bill C-290 and notes Canadians spend billions of dollars gambling illegally on single-game sports by betting online.

Burns noted no U.S. interests are lobbying on the Hill.

The International Olympic Committee, the Collegiate Athletic Association and pro-sports leagues such as the NHL, the NBA and the NFL are all adamantly opposed to the bill, arguing it opens games to match fixing.